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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>

    <script>

        // constructor   构造器

        const arr = [1, 2, 3];

        console.log(arr.constructor)

        console.log(arr.constructor === Array)

        // console.log(arr instanceof Array);  // 


        function Fn() { }

        const f = new Fn();
        console.log(f.constructor)


        function Dog() { }

        const d = new Dog();

        console.log(d.constructor === Dog)

    </script>

</body>

</html>